Chapter IX: Section I: Smell (4)

We are not yet, however, at the end of the difficulty; for it may be objected, that the idea of the absence of anything is the idea of a negation, of a nullity; and the idea of nothing must itself be nothing--no idea at all. This objection has imposed upon more than one metaphysician; but the solution of the paradox is very simple. The idea of the presence of a sensation is the idea of the sensation itself along with certain accompanying circumstances: the idea of the absence of the sensation is the idea of the same accompanying circumstances without the sensation. For example: my idea of a body is the idea of a feeling of resistance, accompanying a certain muscular action of my own, say of my hand; my idea of no body, in other words, of empty space, is the idea of the same or a similar muscular action of my own, not attended by any feeling of resistance. Neither of these is an idea of a mere negation; both are positive mental representations: but inasmuch as one of them includes the negation of something positive which is an actual part of the other, they are mutually incompatible: and any idea which is so associated with one of them as to recall it instantly and irresistibly, is incapable of being associated with the other.

The instance cited by the author from Dr. Brown, is a good illustration of the law. We can associate the ideas of a plane and of a convex surface as two surfaces side by side; but we cannot fuse the two mental images into one, and represent to ourselves the very same series of points giving us the sensations we receive from a plane surface and those we receive from a convex surface both at once. That this cannot but be so, is a corollary from the elementary law of association. Not only has no instance ever occurred in our experience of a surface which gave us at the same moment both these sets of sensations; but whenever in our experience a surface originally plane, came to give us the sensations we receive from a convex surface (as for instance when we bend a flat sheet of paper), it, at the very same moment, ceased to be, or to appear, a plane. The commencement of the one set of sensations has always been simultaneous with the cessation of the other set, and this experience, not being affected by any change of circumstances, has the constancy and invariability of a law of nature. It forms a correspondingly strong association; and we become unable to have an idea of either set of sensations, those of planeness or those of convexity, without having the idea of the disappearance of the other set, if they existed previously. I believe it will be found that all the mental incompatibilities, the impossibilities of thought, of which so much is made by a certain class of metaphysicians, can be accounted for in a similar manner.--_Ed._]

{98} 10. It not unfrequently happens in our associated feelings, that the antecedent is of no importance {99} farther than as it introduces the consequent. In these cases, the consequent absorbs all the attention, {100} and the antecedent is instantly forgotten. Of this a very intelligible illustration is afforded by what happens in ordinary discourse. A friend arrives from a distant country, and brings me the first intelligence of the last illness, the last words, the last acts, and death of my son. The sound of the voice, the articulation of every word, makes its sensation in my ear; but it is to the ideas that my attention flies. It is my son that is before me, suffering, acting, speaking, dying. The words which have introduced the ideas, and kindled the affections, have been as little heeded, as the respiration which has been accelerated, while the ideas were received.

It is important in respect to this case of association {101} to remark, that there are large classes of our sensations, such as many of those in the alimentary duct, and many in the nervous and vascular systems, which serve, as antecedents, to introduce ideas, as consequents; but as the consequents are far more interesting than themselves, and immediately absorb the attention, the antecedents are habitually overlooked; and though they exercise, by the trains which they introduce, a great influence on our happiness or misery, they themselves are generally wholly unknown.

That there are connections between our ideas and certain states of the internal organs, is proved by many familiar instances. Thus, anxiety, in most people, disorders the digestion. It is no wonder, then, that the internal feelings which accompany indigestion, should excite the ideas which prevail in a state of anxiety. Fear, in most people, accelerates, in a remarkable manner, the vermicular motion of the intestines. There is an association, therefore, between certain states of the intestines, and terrible ideas; and this is sufficiently confirmed by the horrible dreams to which men are subject from indigestion; and the hypochondria, more or less afflicting, which almost always accompanies certain morbid states of the digestive organs. The grateful food which excites pleasurable sensations in the mouth, continues them in the stomach; and, as pleasures excite ideas of their causes, and these of similar causes, and causes excite ideas of their effects, and so on, trains of pleasurable ideas take their origin from pleasurable sensations in the stomach. Uneasy sensations in the stomach, produce analogous effects. Disagreeable sensations are {102} associated with disagreeable circumstances: a train is introduced, in which, one painful idea following another, combinations, to the last degree afflictive, are sometimes introduced, and the sufferer is altogether overwhelmed by dismal associations.[31] [32]

[Bain's footnote 31: There is more than association in the case here supposed. Fear, anxiety, and painful emotions generally, cause disorder in the digestive and other vital functions, as a part of their nature. Every mental state can be proved to have its counterpart physical state; joy, sorrow, fear, are each embodied in a distinct group of physical effects in the nervous system, the muscular movements, and the organic processes. The physical side of agreeable emotions, as a rule, is a heightened tone of the purely animal functions. The physical side of fear is a complicated series of effects, one of them being the depression of the organic processes, digestion among the rest. In this respect, however, it more or less resembles severe pain, sorrow, shame, remorse, and other states, characterised by the general phrase "depressing passions;" the depression being both mental and physical.

The reciprocal agency described in the text, whereby the painful sensations of indigestion induce fear, is not dependent on the association of ideas, but on the deep connections of the emotional states with one another, through their physical accompaniments. A painful feeling of indigestion has much in common with states of depression due to mental causes, as, for example, the shock of a misfortune, fear, sorrow, and the like. From this alliance it favours the ideas of depressing states. It does more; it directly reduces that vigorous tone of the system, which is the support of the courageous and sanguine disposition; and hence, surrenders the mind an easy prey to any chance incentive of alarm or anxiety.--_B._]

[Editor's footnote 32: The law of association laid down in this section ranks among the principal of what may be termed the laws of Obliviscence. It is one of the widest in its action, and most important in its consequences of all the laws of the mind; and the merit of the author, in the large use he makes of it is very great, as, though it is the key that unlocks many of the more mysterious phenomena of the mind, it is among the least familiar of the mental laws, and is not only overlooked by the great majority of psychologists, but some, otherwise of merit, seem unable to see and understand the law after any quantity of explanation.

The first, however, of the examples by which the author illustrates this law, is not marked by his usual felicity. Its shortcomings are pointed out by Mr. Bain in the preceding note. The internal feelings (says the author) which accompany indigestion, introduce trains of ideas (as in the case of horrible dreams, and of hypochondria) which are acutely painful, and may embitter the whole existence, while the sensations themselves, being comparatively of little interest, are unheeded and forgotten. It is true that the sensations in the alimentary canal, directly produced by indigestion, though (as every one knows) in some cases intense, are in others so slight as not to fix the attention, and yet may be followed by melancholy trains of thought, the connection of which with the state of the digestion may be entirely unobserved: but by far the most probable supposition appears to be, that these painful trains are not excited by the sensations, but that they and the sensations are joint or successive effects of a common organic cause. It is difficult to comprehend how these obscure sensations can excite the distressing trains of ideas by the laws of association; for what opportunity have these sensations usually had of becoming associated, either synchronously or successively, with those ideas? The explanation, in the text, of this difficulty, seems surprisingly insufficient. Anxiety, in most people, disorders the digestion; and consequently, according to the author, the sensations of indigestion excite the ideas which prevail in a state of anxiety. If that were the true explanation, the only persons with whom indigestion would depress the spirits, would be those who had suffered previous depression of spirits, sufficient in duration and intensity to disorder the digestion, and to keep it disordered long enough to effect a close and inseparable cohesion between even very slight sensations of indigestion and painful ideas excited by other causes. Surely this is not the fact. The theory has a true application in the case of the confirmed hypochondriac. When the sensations have been repeatedly experienced along with the melancholy trains of thought, a direct association is likely to grow up between the two; and when this has been effected, the first touch of the sensations may bring back in full measure the miserable mental state which had coexisted with them, thus increasing not only the frequency of its recurrence, but, by the conjunction of two exciting causes, the intensity of the misery. But the origin of the state must be looked for elsewhere, and is probably to be sought in physiology.

The other example in the text seems still less relevant. Fear tends to accelerate the peristaltic motion, therefore there is a connection between certain states of the intestines and terrible ideas. To make this available for the author's purpose, the consequence of the connection ought to be, that acceleration of the peristaltic motion excites ideas of terror. But does it? The state of indigestion characteristic of hypochondria is not looseness of the bowels, but is commonly attended with the exact opposite. The author's usual acuteness of discernment seems to have been, in these cases, blunted by an unwillingness to admit the possibility that ideas as well as sensations may be directly affected by material conditions. But if, as he admits, ideas have a direct action on our bodily organs, a _prima facie_ case is made out for the localization of our ideas, equally with our sensations, in some part of our bodily system; and there is at least no antecedent presumption against the supposition that the action may be reciprocal--that as ideas sometimes derange the organic functions, so derangements of organic functions may sometimes modify the trains of our ideas by their own physical action on the brain and nerves, and not through the associations connected with the sensations they excite.--_Ed._]

{103} In illustration of the fact, that sensations and ideas, which are essential to some of the most important {104} operations of our minds, serve only as antecedents to more important consequents, and are themselves so {105} habitually overlooked, that their existence is unknown, we may recur to the remarkable case which we have just explained, of the ideas introduced by the sensations of sight. The minute gradations of colour, which accompany varieties of extension, figure, and distance, are insignificant. The figure, the size, the distance, themselves, on the other hand, are matters of the greatest importance. The first having introduced the last, their work is done. The consequents remain the sole objects of attention, the antecedents are forgotten; in the present instance, not completely; in other instances, so completely, that they cannot be recognised.[33] [34]

[Bain's footnote 33: Perhaps the most remarkable case of sensations overlooked on their own account, and considered only as a means of suggesting something else, is the visual, or retinal, magnitude of objects seen by the eye. This is probably the most delicate sensibility within the compass of the mind; and yet we habitually disregard it for all things near us, and use it solely for perceiving real magnitude as estimated by our locomotive and other members. The visual magnitude of a table, or other article in a room, is never thought of for itself; although incessantly fluctuating we never think of the fluctuations; we pass from these to the one constant perception, named the true or real magnitude. It is only for remote objects, as the sun and moon, the clouds, the distant hills, that the retinal magnitude abides with us in its own proper character. In looking down a vista, we may also be aroused to the feeling of retinal magnitude. For perspective drawing, it is necessary that we should arrest the strong tendency to pass from the visible, to the real, forms and dimensions of things.--_B._]

[Editor's footnote 34: The reader, it may be hoped, is now familiar with the important psychological fact, so powerfully grasped and so discerningly employed by Hartley and the author of the Analysis,--that when, through the frequent repetition of a series of sensations, the corresponding train of ideas rushes through the mind with extreme rapidity, some of the links are apt to disappear from consciousness as completely as if they had never formed part of the series. It has been a subject of dispute among philosophers which of three things takes place in this case. Do the lost ideas pass through the mind without consciousness? Do they pass consciously through the mind and are they then instantly forgotten? Or do they never come into the mind at all, being, as it were, overleaped and pressed out by the rush of the subsequent ideas?

It would seem, at first sight, that the first and third suppositions involve impossibilities, and that the second, therefore, is the only one which we are at liberty to adopt. As regards the first, it may be said--How can we have a feeling without feeling it, in other words, without being conscious of it? With regard to the third, how, it may be asked, can any link of the chain have been altogether absent, through the pressure of the subsequent links? The subsequent ideas are only there because called up by it, and would not have arisen at all unless it had arisen first, however short a time it may have lasted. These arguments seem strong, but are not so strong as they seem.

In favour of the first supposition, that feelings may be unconsciously present, various facts and arguments are adduced by Sir William Hamilton in his Lectures; but I think I have shewn in another work, that the arguments are inconclusive, and the facts equally reconcilable with the second of the three hypotheses. That a feeling should not be felt appears to me a contradiction both in words and in nature. But, though a feeling cannot exist without being felt, the organic state which is the antecedent of it may exist, and the feeling itself not follow. This happens, either if the organic state is not of sufficient duration, or if an organic state stronger than itself, and conflicting with it, is affecting us at the same moment. I hope to be excused for quoting what I have said elsewhere on this subject (Examination of Sir William Hamilton's Philosophy, ch. 15).

"In the case, for instance, of a soldier who receives a wound in battle, but in the excitement of the moment is not aware of the fact, it is difficult not to believe that if the wound had been accompanied by the usual sensation, so vivid a feeling would have forced itself to be attended to and remembered. The supposition which seems most probable is, that the nerves of the particular part were affected as they would have been by the same cause in any other circumstances, but that, the nervous centres being intensely occupied with other impressions, the affection of the local nerves did not reach them, and no sensation was excited. In like manner, if we admit (what physiology is rendering more and more probable) that our mental feelings, as well as our sensations, have for their physical antecedents particular states of the nerves; it may well be believed that the apparently suppressed links in a chain of association, those which Sir William Hamilton considers as latent, really are so; that they are not, even momentarily, felt; the chain of causation being continued only physically, by one organic state of the nerves succeeding another so rapidly that the state of mental consciousness appropriate to each is not produced. We have only to suppose, either that a nervous modification of too short duration does not produce any sensation or mental feeling at all, or that the rapid succession of different nervous modifications makes the feelings produced by them interfere with each other, and become confounded in one mass. The former of these suppositions is extremely probable, while of the truth of the latter we have positive proof. An example of it is the experiment which Sir W. Hamilton quoted from Mr. Mill, and which had been noticed before either of them by Hartley. It is known that the seven prismatic colours, combined in certain proportions, produce the white light of the solar ray. Now, if the seven colours are painted on spaces bearing the same proportion to one another as in the solar spectrum, and the coloured surface so produced is passed rapidly before the eyes, as by the turning of a wheel, the whole is seen as white. The physiological explanation of this phenomenon may be deduced from another common experiment. If a lighted torch, or a bar heated to luminousness, is waved rapidly before the eye, the appearance produced is that of a ribbon of light; which is universally understood to prove that the visual sensation persists for a certain short time after its cause has ceased. Now, if this happens with a single colour, it will happen with a series of colours: and if the wheel on which the prismatic colours have been painted, is turned with the same rapidity with which the torch was waved, each of the seven sensations of colour will last long enough to be contemporaneous with all the others, and they will naturally produce by their combination the same colour as if they had, from the beginning, been excited simultaneously. If anything similar to this obtains in our consciousness generally (and that it obtains in many cases of consciousness there can be no doubt) it will follow that whenever the organic modifications of our nervous fibres succeed one another at an interval shorter than the duration of the sensations or other feelings corresponding to them, those sensations or feelings will, so to speak, overlap one another, and becoming simultaneous instead of successive, will blend into a state of feeling, probably as unlike the elements out of which it is engendered, as the colour white is unlike the prismatic colours. And this may be the source of many of those states of internal or mental feeling which we cannot distinctly refer to a prototype in experience, our experience only supplying the elements from which, by this kind of mental chemistry, they are composed. The elementary feelings may then be said to be latently present, or to be present but not in consciousness. The truth, however, is that the feelings themselves are not present, consciously or latently, but that the nervous modifications which are their usual antecedents have been present, while the consequents have been frustrated, and another consequent has been produced instead."

In this modified form, therefore, the first of the three hypotheses may possibly be true. Let us now consider the third, that of the entire elision of some of the ideas which form the associated train. This supposition seemed to be inadmissible, because the loss of any link would, it was supposed, cause the chain itself to break off at that point. To make the hypothesis possible, it is only, however, necessary to suppose, that, while the association is acquiring the promptitude and rapidity which it ultimately attains, each of the successive ideas abides for a brief interval in our consciousness after it has already called up the idea which is to succeed it. Each idea in the series, though introduced, not by synchronous, but by successive association, is thus, during a part of its continuance, synchronous with the idea which introduced it: and as the rapidity of the suggestions increases by still further repetition, an idea may become synchronous with another which was originally not even contiguous to it, but separated from it by an intervening link; or may come into immediate instead of mediate sequence with such an idea. When either of these states of things has continued for some time, a direct association of the synchronous or of the successive kind will be generated between two ideas which are not proximate links in the chain; A will acquire a direct power of exciting C, independently of the intervening idea B. If, then, B is much less interesting than C, and especially if B is of no importance at all in itself, but only by exciting C, and has therefore nothing to make the mind dwell on it after C has been reached, the association of A with C is likely to become stronger than that of A with B: C will be habitually excited directly by A; as the mind runs off to the further ideas suggested by C, B will cease to be excited at all; and the train of association, like a stream which breaking though its bank cuts off a bend in its course, will thenceforth flow in the direct line AC, omitting B. This supposition accounts more plausibly than either of the others for the truly wonderful rapidity of thought, since it does not make so large a demand as the other theories on our ability to believe that a prodigious number of different ideas can successively rush through the mind in an instant too short for measurement.

The result is, that all the three theories of this mental process seem to be quite possible; and it is not unlikely that each of them may be the real process in some cases, either in different persons, or in the same persons under different circumstances. I can only remit the question to future psychologists, who may be able to contrive crucial experiments for deciding among these various possibilities.--_Ed._]

{106} 11. Mr. Hume, and after him other philosophers, have said that our ideas are associated according to {107} three principles; Contiguity in time and place, Causation, and Resemblance. The Contiguity in time and {108} place, must mean, that of the sensations; and so far it is affirmed, that the order of the ideas follows that {109} of the sensations. Contiguity of two sensations in time, means the successive order. Contiguity of two {110} sensations in place, means the synchronous order. We have explained the mode in which ideas are associated, in the synchronous, as well as the successive order, and have traced the principle of contiguity to its proper source.

Causation, the second of Mr. Hume's principles, is the same with contiguity in time, or the order of succession. Causation is only a name for the order established between an antecedent and a consequent; that is, the established or constant antecedence of the one, {111} and consequence of the other. Resemblance only remains, as an alleged principle of association, and it is necessary to inquire whether it is included in the laws which have been above expounded. I believe it will be found that we are accustomed to see like things together. When we see a tree, we generally see more trees than one; when we see an ox, we generally see more oxen than one; a sheep, more sheep than one; a man, more men than one. From this observation, I think, we may refer resemblance to the law of frequency, of which it seems to form only a particular case.[35]

[Editor's footnote 35: The reason assigned by the author for considering association by resemblance as a case of association by contiguity, is perhaps the least successful attempt at a generalisation and simplification of the laws of mental phenomena, to be found in the work. It ought to be remembered that the author, as the text shows, attached little importance to it. And perhaps, not thinking it important, he passed it over with a less amount of patient thought than he usually bestowed on his analyses.

Objects, he thinks, remind us of other objects resembling them, because we are accustomed to see like things together. But we are also accustomed to see like things separate. When two combinations incompatible with one another are both realised in familiar experience, it requires a very great preponderance of experience on one side to determine the association specially to either. We are also much accustomed to see unlike things together; I do not mean things contrasted, but simply unlike. Unlikeness, therefore, not amounting to contrast, ought to be as much a cause of association as likeness. Besides, the fact that when we see (for instance) a sheep, we usually see more sheep than one, may cause us, when we think of a sheep, to think of an entire flock; but it does not explain why, when we see a sheep with a black mark on its forehead, we are reminded of a sheep with a similar mark, formerly seen, though we never saw two such sheep together. It does not explain why a portrait makes us think of the original, or why a stranger whom we see for the first time reminds us of a person of similar appearance whom we saw many years ago. The law by which an object reminds us of similar objects which we have been used to see along with it, must be a different law from that by which it reminds us of similar objects which we have not been used to see along with it. But it is the same law by which it reminds us of dissimilar objects which we have been used to see along with it. The sight of a sheep, if it reminds us of a flock of sheep, probably by the same law of contiguity, reminds us of a meadow; but it must be by some other law that it reminds us of a single sheep previously seen, and of the occasion on which we saw that single sheep.

The attempt to resolve association by resemblance into association by contiguity must perforce be unsuccessful, inasmuch as there never could have been association by contiguity without a previous association by resemblance. Why does a sensation received this instant remind me of sensations which I formerly had (as we commonly say), along with it? I never had them along with this very sensation. I never had this sensation until now, and can never have it again. I had the former sensations in conjunction not with it, but with a sensation exactly like it. And my present sensation could not remind me of those former sensations unlike itself, unless by first reminding me of the sensation like itself, which really did coexist with them. There is thus a law of association anterior to, and presupposed by, the law of contiguity: namely, that a sensation tends to recall what is called the idea of itself, that is, the remembrance of a sensation like itself, if such has previously been experienced. This is implied in what we call _recognising_ a sensation, as one which has been felt before; more correctly, as undistinguishably resembling one which has been felt before. The law in question was scientifically enunciated, and included, I believe for the first time, in the list of Laws of Association, by Sir William Hamilton, in one of the Dissertations appended to his edition of Reid: but the fact itself is recognised by the author of the Analysis, in various passages of his work; more especially in the second section of the fourteenth chapter. There is, therefore, a suggestion by resemblance--a calling up of the idea of a past sensation by a present sensation like it--which not only does not depend on association by contiguity, but is itself the foundation which association by contiguity requires for its support.

When it is admitted that simple sensations remind us of one another by direct resemblance, many of the complex cases of suggestion by resemblance may be analysed into this elementary case of association by resemblance, combined with an association by contiguity. A flower, for instance, may remind us of a former flower resembling it, because the present flower exhibits to us certain qualities, that is, excites in us certain sensations, resembling and recalling to our remembrance those we had from the former flower, and these recall the entire image of the flower by the law of association by contiguity. But this explanation, though it serves for many cases of complex phenomena suggesting one another by resemblance, does not suffice for all. For, the resemblance of complex facts often consists, not solely, or principally, in likeness between the simple sensations, but far more in likeness of the manner of their combination, and it is often by this, rather than by the single features, that they recall one another. After we had seen, and well observed, a single triangle, when we afterwards saw a second there can be little doubt that it would at once remind us of the first by mere resemblance. But the suggestion would not depend on the sides or on the angles, any or all of them; for we might have seen such sides and such angles uncombined, or combined into some other figure. The resemblance by which one triangle recalls the idea of another is not resemblance in the parts, but principally and emphatically in the manner in which the parts are put together. I am unable to see any mode in which this case of suggestion can be accounted for by contiguity; any mode, at least, which would fit all cases of the kind.--_Ed._]

{112} Mr. Hume makes contrast a principle of association, but not a separate one, as he thinks it is compounded {113} of Resemblance and Causation. It is not necessary for us to show that this is an unsatisfactory account {114} of contrast. It is only necessary to observe, that, as a case of association, it is not distinct from those which we have above explained.

A dwarf suggests the idea of a giant. How? We call a dwarf a dwarf, because he departs from a certain standard. We call a giant a giant, because he departs from the same standard. This is a case, therefore, of resemblance, that is, of frequency.

Pain is said to make us think of pleasure; and this is considered a case of association by contrast. There is no doubt that pain makes us think of relief from it; because they have been conjoined, and the great vividness of the sensations makes the association strong. Relief from pain is a species of pleasure; and one pleasure leads to think of another, from the resemblance. This is a compound case, therefore, of vividness and frequency. All other cases of contrast, I believe, may be expounded in a similar manner.

I have not thought it necessary to be tedious in expounding the observations which I have thus stated; for whether the reader supposes that resemblance is, or is not, an original principle of association, will not affect our future investigations.

12. Not only do simple ideas, by strong association, run together, and form complex ideas: but a {115} complex idea, when the simple ideas which compose it have become so consolidated that it always appears as one, is capable of entering into combinations with other ideas, both simple and complex. Thus two complex ideas may be united together, by a strong association, and coalesce into one, in the same manner as two or more simple ideas coalesce into one. This union of two complex ideas into one, Dr. Hartley has called a duplex idea.[37] Two also of these duplex, or doubly compounded ideas, may unite into one; and these again into other compounds, without end. It is hardly necessary to mention, that as two complex ideas unite to form a duplex one, not only two, but more than two may so unite; and what he calls a duplex idea may be compounded of two, three, four, or any number of complex ideas.

[Editor's footnote 37: I have been unable to trace in Hartley the expression here ascribed to him. In every passage that I can discover, the name he gives to a combination of two or more complex ideas is that of a _decomplex_ idea.--_Ed._]

Some of the most familiar objects with which we are acquainted furnish instances of these unions of complex and duplex ideas.

Brick is one complex idea, mortar is another complex idea; these ideas, with ideas of position and quantity, compose my idea of a wall. My idea of a plank is a complex idea, my idea of a rafter is a complex idea, my idea of a nail is a complex idea. These, united with the same ideas of position and quantity, compose my duplex idea of a floor. In the same manner my complex idea of glass, and wood, and others, compose my duplex idea of a window; and {116} these duplex ideas, united together, compose my idea of a house, which is made up of various duplex ideas. How many complex, or duplex ideas, are all united in the idea of furniture? How many more in the idea of merchandize? How many more in the idea called Every Thing?[38] [39]

[Bain's footnote 38: This chapter raises questions of the most fundamental kind relating to our intellectual constitution. The Association of Ideas, comprehensively viewed, involves everything connected with the mental persistence and reproduction of ideas; being offered as adequate to explain the operations named Memory, Reason, and Imagination.

_Conditions of the Growth of Association, or of the Retentiveness of the Mind_.--A practical, as well as a theoretical, interest attaches to the precise statement of the conditions or circumstances that regulate the growth of our associations, in other words our mental culture generally. All agree in the efficacy of the two conditions mentioned in the text; the vividness of the feelings associated, and the frequency of the association, that is repetition or practice. It is well remarked, however, that the phrase "vividness of the sensations or ideas" does not convey a very precise meaning. The proper attribute of a sensation, or an idea, considered as an _intellectual_ element, is greater or less distinctness; when an object seen or remembered is seen or remembered distinctly and fully, and without any unusual labour or effort, there is nothing more to be desired, so far as concerns our intelligence. If, however, the object is accompanied with _feeling_--with pleasure or pain--a new element is introduced, to which other epithets are applicable. A feeling is more or less strong or intense; and the addition of an intense feeling to an intellectual conception is a sum, combining both sets of attributes--distinctness and adequacy in the conception, and intensity in the feeling. An object whose perception or conception is thus accompanied with the animation of strong feeling, is called lively, or vivid; {117} in the absence of feeling, these epithets are unsuitable. Hence, the associating stimulus expressed by "vividness" is better expressed by the "strength of the feelings." Any strong feeling impresses on the mind whatever is the object of it, or is in any way mixed up with it. We remember by preference the things that have given us either pleasure or pain; and the effect may be produced by mere excitement although neither pleasurable nor painful; the influence of a surprise being a case in point. Our _interest_ in a thing is but another name for the pleasure that it gives us; and to inspire interest is to aid the memory. Hamilton's Law of Preference refers to this source; and appears to exclude, or not to recognise, the efficacy of feelings not pleasurable, namely, such as are either painful or neutral. The comprehensive law should include all the feelings, although there are specific characters attaching to the influence of each of the three modes. Pleasure is the most effectual in stamping the memory, as it is the most powerful in detaining the attention and the thoughts. Pain has a conflicting operation; as affecting the will, it repels the object; but as mere excitement it retains it; we cannot forget what is disagreeable, merely because we wish to forget it. The stimulant of pain, as applied in education, is an indirect pleasure. It is not intended to make the subject of the lesson disagreeable, but to render painful all diversions from that towards other subjects; so that comparatively the most pleasing course to a pupil may be to abide by the task prescribed.

The influence of the Feelings upon Retentiveness is not throughout in proportion to their degree, whether they are pleasurable, painful, or neutral. We have to introduce a modifying circumstance into the case, namely, that great strength of feeling absorbs the forces of the system, and diminishes the power available for cementing an intellectual association. A strong feeling once aroused, while inflaming the attention upon whatever is bound up with it, necessarily engages us with itself. The plastic process of fixing a train or aggregate of ideas has but a share of the energies awakened under feeling.

It is possible also to stimulate attention, and thereby to {118} quicken memory, without the excitement of the feelings, as in pure voluntary attention. For although the will, in the last resort, is stimulated by an end (which must involve the feelings), yet we may be strongly moved without being under the excitement of the feelings that enter into the final end. Our volitions may be energetic, without the presence of strong emotions, notwithstanding that, apart from our possessing such emotions, we should not be strongly moved to action. Thus, a difference is made between the influence of the feelings and the influence of the will; both being powers to impress the memory.

The two considerations now advanced, namely, the want of strict concomitance between strength of feeling and the stimulus to memory, and the operation of the will in the abeyance of present feeling, make it desirable to find some other mode of stating the element or condition that qualifies the influence of Frequency or Repetition, in the growth of memory and association. Perhaps the best mode of singling out the operative circumstance is to describe it as "Concentration of Mind;" the devotion of the mental forces to the thing to be done or remembered--the withdrawal of power from other exercises, to expend it on the exercise in hand. Every circumstance that at once rouses the mental and nervous energies, and keeps them fixed upon any subject of study or the practice of any art, is a circumstance in aid of acquisition. No fact more comprehensive, more exactly in point, can be assigned than the one now stated. What remains is to apply it in the detail, or to point out the occasions and conditions that favour, and those that obstruct, the concentration of the mental energy. It is under this view that we can best appreciate the efficacy of pleasure (interest in the subject), of pain, of mere excitement, and of voluntary attention. We can also see, as an obvious corollary, the advantage of having the mind unoccupied, or disengaged for the work, and the disadvantage of being diverted, or distracted by other objects. Fear, care, anxiety, are hostile to culture by lowering the tone or energy of the mind; while what power is left concentrates itself upon the subject matter of the anxious feeling. On the other hand, general vigour of the {119} system, good health, easy circumstances, are all in favour of mental improvement, provided the force thus made available can be reserved and devoted to that end.

Thus the two leading conditions of the plastic process are Frequency of Repetition, and Mental Concentration. For practical purposes, these are all that we need to consider, at least as regards the same individual. We have no art or device for training either body or mind but what is comprised under one or other of these heads. There are methods of superseding the labour of new acquirement, by adapting existing acquirements to new cases; but no means can be assigned for the original construction of adhesive links, apart from these two circumstances.

Still, in a large and exhaustive view of the Retentive power of the mind, we should not omit to allow for the differences between one mind and another in respect of Natural Aptitude for acquiring. When two persons engaged in the same lesson, for equal periods of time, and with about equal concentration of mind, make very unequal progress, we must admit a difference in natural or constitutional plasticity on that particular subject. Sometimes we find extraordinary progress made in acquisition generally; the same person excelling in languages, in sciences, in practical arts, and in fine arts. More commonly, however, we find an aptitude for some subject in particular, combined with deficiency in other things. One person has great mechanical acquirements, another lingual, and so on.

The first case is sufficiently common to justify the assumption of degrees of acquisitive or plastic aptitude on the whole, or a variety in the cerebral endowment corresponding to the adhesion of trains of actions and ideas that have been more or less frequently brought together. If the differences among human beings are not so broad as to make this apparent, we may refer to the differences between the lower animals and man. The animals have the power of acquiring, but so limited is that power in comparison with human beings, that people have often doubted its existence.

{120} The second case, the inequality of the same person's progress in different subjects, may be looked at in another way. We may view it as incident to the better or worse quality, for all purposes, of the special organs concerned. Thus to take musical acquisition. This is commonly attributed to a good ear, meaning a delicate sense of musical notes, as shown in their nice discrimination. Discriminating is a different function from remembering; yet, we can only doubt that the fact of being able to discriminate acutely is accompanied by the power of remembering or retaining the impressions of the sense. The superiority of endowment that shows itself in the one function, embraces also the other. Hence we are entitled to say that the special retentiveness for any one subject, or department of training, varies with the local endowment involved: which is not to maintain an identical proposition, for the local endowment may be held as tested by delicacy of discrimination, a distinct fact from memory. Thus, a delicate sense of shades of colour would entail a good visual memory for spectacle; a delicate ear for articulation would indicate a memory for shades and varieties of pronunciation, thereby counting as a part of the verbal memory. So, delicate discrimination in the tactile muscles would be followed by rapid acquirements in manipulative or manual art.

_The Ultimate Analysis of the Laws of Association_.--It is easy to reduce all the laws ever assigned, as governing the reproduction of our ideas, to three, Contiguity, Similarity, and Contrast. It is open to question whether these can be resolved any farther. The author has endeavoured to reduce Similarity to Contiguity, but his reasons show that he had not deeply considered the workings of similarity. Hamilton's criticisms on the attempt (Reid, p. 914) are just and irrefragable. By far the most important examples of the working of similarity are such as, by their very nature, preclude a former contiguity: as, for example, Franklin's identification of Electricity and lightning.

There is, nevertheless, a considerable degree of subtlety in the relationship of the two principles. There may be good reasons {121} for treating them as distinct, but in their working they are inextricably combined. There can be no contiguity without similarity, and no similarity without contiguity. When, looking at a river, we pronounce its name, we are properly said to exemplify contiguity; the river and the name by frequent association are so united that each recalls the other. But mark the steps of the recall. What is strictly present to our view is the impression made by the river while we gaze on it. It is necessary that this impression should, by virtue of similarity or identity, re-instate the previous impression of the river, to which the previous impression of the name was contiguous. If one could suppose failure in the re-instatement of the former idea of the river, under the new presentation, there would be no opportunity given to the contiguous bond to come into operation. In that accumulation of the impressions of contiguous ideas, ending at last in a firm association, there must be a process of similarity to the extent of reviving the sum of the past at the instance of the present. This is a case of similarity that we give little heed to, because it is sure and unfailing; we concern ourselves more with what is liable to uncertainty, the acquired strength of the contiguous adhesion. Yet it strictly comes under the case of reproduction through similarity.

Consider again, what may be called a case of Similarity proper, as when a portrait recalls the original. The sensuous effects possessed in common by the portrait and by its subject bring about a restoration of the idea of the subject, in spite of certain differences or discrepancies. The interest of this case is owing to the fact that a partial likeness, a likeness in unlikeness, will often reproduce a past idea; thus enabling us to assemble in the mind a number of things differing in some respects because they agree in other respects. This is not identifying a thing with itself, viewed at a former time, but assimilating one thing with other things placed far asunder in nature, and having many features of difference.

Let us try and express the consecutive steps of this case of reproduction. The thing now present to the mind has certain {122} peculiarities in common with one or more things formerly present; as when, in a portrait, the outline and colouring resembles a subject original. These sensible effects make alive the previous recurrence of them, or put us in the cerebral and mental attitude formerly experienced by the corresponding effects of the resembling object. We are aware, by the liveliness of our impression, that we have gone in upon an old track; we have the peculiar consciousness called the consciousness of Identity or Agreement. This is one step, but not the whole. In order that the complete restoration may be effected, the features of community must be in such firm contiguous alliance with the features of difference--the _special_ part of the previous subject that the one shall reinstate the idea of the other. The points common to a present portrait and a past original must be so strongly coherent with the remaining features of the original, that the one cannot be awakened without the other following. Here, then, in the very heart of Similarity, is an indispensable bond of Contiguity; showing that it is not possible for either process to be accomplished in separation from the other. The mutual coherence of parts, now described as essential to reproduction, may be too weak for the purpose, and the recovering stroke of similarity will in that case fail.

It might, therefore, be supposed that Similarity is, after all, but a mode of Contiguity, namely, the contiguity or association of the different features or parts of a complex whole. The inference is too hasty. Because contiguity is a part of the fact of the restoration of similars, it is not the entire fact. There is a distinct and characteristic step preceding the play of this mutual coherence of the parts of the thing to be recovered. The striking into the former track of the agreeing part of the new and the old, is a mental movement by itself, which the other follows, but does not do away with. The effect above described, as the consciousness of agreement or identity, the flash of a felt similarity, is real and distinct. We are conscious of it by itself; there are occasions when we have it without the other, that is to say, without the full re-instatement of the former {123} object in its entireness. We often aware of an identity without being able to say what is the thing identified; as when a portrait gives us the impression that we have seen the original, without enabling us to say who the original is. We have been affected by the stroke of identity or similarity; but the restoration fails from the feebleness of the contiguous adherence of the parts of the object identified. There is thus a genuine effect of the nature of pure similarity, or resemblance, and a mode of consciousness accompanying that effect; but there is not the full energy of reproduction without a concurring bond of pure contiguity. A portrait may fail to give us the consciousness of having ever seen the original. On the supposition that we have seen the original, this would be a failure of pure similarity.

Thus in every act of reproducing a past mental experience, there is a complication, involving both contiguity proper and similarity proper. When the similarity amounts to identity, as when a new impression of a thing puts us in the track of the old impressions of the same thing, the effect is so sure, so obvious, so easily arrived at, that we do not need to think of it, to make a question of it. It does not prevent us from regarding the operation of recalling a name when we see the thing, or recalling a thing when we hear the name, as pure contiguity. The strength of the coherence may be deficient, and the restoration may fail on this account; it can never fail on account of insufficient similarity. No inconvenience will arise from speaking of this case as if it were Contiguity and nothing else.

The situation of Similarity in Diversity is quite distinct. The diversity obstructs the operation of similarity; we cannot be sure that the new shall put us on the track of the old. It is always a question whether such similarities shall be felt at all; whether we shall experience the flash, the peculiar consciousness, of agreement in difference. It is a farther question, whether the internal coherence of the thing identified is enough to restore it in completeness. This last step may be allowed to be a case of proper contiguity; while the flash of identity struck between a present and a past, never coupled in the {124} mind before, is an effect _sui generis_, and not resolvable into any mode or incident of contiguity.

The circumstances of this identifying stroke are so numerous and far-reaching as to demand a special exemplification. Some of the broadest distinctions of intellectual character can be grounded on the distinctive aptitudes of the mind for Contiguity and for Similarity.

Learning, Acquisition, Memory, Habit, all designate the plastic adherence of contiguous impressions. The processes of Classification, Reasoning, Imagination, and the Inventive faculty generally, depend upon the identifying stroke of likeness in unlikeness. Some forms of intellectual strength, as a whole, are best represented by a highly energetic Adhesiveness; distinction as a learner, a follower of routine, turns upon this power. Other, and higher, forms of intelligence depend upon far-reaching strokes of similarity; the identification of likeness shrouded in diversity, expresses much of the genius of the poet, the philosopher, the man of practice.

There remains the consideration of Contrast, as a link of association. It is easy to show that both Contiguity and Similarity may enter into the association of contrasts. All contrasts that we are interested in are habitually coupled in language, as light and dark, heat and cold, up and down, life and death. Again contrasts suppose a common genus, that is a generic similarity; at least until we ascend to the highest contrast of all, the subject mind, and the object or extended world. Cold and Hot are grades of the common attribute called Temperature. As these links of contiguity and similarity are present, and of considerable strength, they practically lead to the mutual suggestion of contrasting things.